Power supplies of various types have been in existence for many years. The present invention addresses a power supply problem for driving a device such as a thermal printer which requires a relatively high current at a low voltage for intermittent periods of time in order to operate properly.
The power supply of the present invention is designed for use where the input voltage can vary widely and where the limited current sourcing capability of this input power source is not necessarily sufficient for driving the desired device (such as a thermal printer). To achieve the required output current and voltage for driving a thermal printer, the present invention incorporates both a step-up switching voltage converter module for charging a high energy storage capacity capacitor to a desired energy level as well as a step-down switching voltage regulator module for using the energy stored in the capacitor for generating the high current required for the thermal printer. Circuitry of this type for use in a power supply is believed to be new and unobvious in view of the prior art.